Synthesis of 1-tetrazolyl-substituted 2,3,4,9-tetrahydro-1 H-β-carbolines and their transformations involving activated alkynes.

1-Tetrazolyl-substituted tetrahydro-β-carbolines undergo a reaction with activated alkynes (acetylacetylene, methyl propiolate, and dimethyl acetylenedicarboxylate) over 4-8 days in MeOH or 1 day in CF3CH2OH with the formation of multicomponent mixtures, from which spiro[indole-3,4'-pyridines] were isolated chromatographically. Additionally, two azocino[5,4- b]indoles were isolated from methyl propiolate and acetylacetylene reactions. [ABSTRACT FROM AUTHOR]